A lot of stuff I've looked at points to 540def 23k hp 23k armor for prot warriors. I don't usually like stuff like this, partly because a person could have 25k hp and 21k armor and be ok. Mostly because you're a guild and you have limited resources, I'd sugest just take what you can get. If your tank is a little bit low to clear the entire raid it doesn't mean you don't go. People are there to raid. I'll give you an example of what my last guild looked like on my first run of OS.
I MT'd (warrior) with ~23k hp, 22k armor, 543def and a good deal of experience tanking various raid bosses at most stages of the game.
The OT was actually a little better geared than I was but they had me do it because I have more boss experience.
We had dpsers ranging between half epics and just finished leveling greens.
Our healers were pretty solid, though not necessarily epic quality.
I came something like 3rd place on the damage meter for sarth with 1.4k sustained dps. We downed him pretty easy. We wiped once, and it was because people couldn't dodge the flame waves. 6-7 of us had never researched or seen the fight. Get your tanks and healers in some heroic gear and get your dpsers to pay attention and you'll probably start getting 10 mans on farm.
If tanks could wield kittens would that make us more or less threatening?
Bookmarks